Shell-type catalyst for gas-phase oxidation of C-C4 hydrocarbons to maleic anhydride, method for producing the same, and gas-phase oxidation of C-C4 hydrocarbons

摘要

There is a process for producing coated catalysts for the gas-phase oxidation of C4 hydrocarbons to maleic anhydride. A vanadyl phosphate catalyst precursor is prepared having a V/P ratio of from 1:0.5 to 1:2 and a mean vanadium oxidation state of from 3.9 to 4.5. The vanadyl phosphate precursor is then calcined by heating for a several hours at a temperature of from 200 DEG C. to 500 DEG C. before being applied, in an aqueous suspension to the support bodies. Furthermore, there is the use of these coated catalysts in processes for the gas-phase oxidation of saturated or unsaturated C4-hydrocarbons to maleic anhydride.